package cn.edu.scau.cmi.shishuai.exercise7;

interface CompurerAverage{
	public double average(double a, double b);
}

class A implements CompurerAverage{
	public double average(double a, double b) {
		double aver = 0;
		aver = (a + b) / 2;
		return aver;
	}
}

class B implements CompurerAverage{
	public double average(double a, double b) {
		double aver = 0;
		aver = Math.sqrt(a * b);
		return aver;
	}
}

public class Example7_3 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		CompurerAverage computer;
		double a = 111.23, b = 22.79;
		computer = new A();
		double result = computer.average(a, b);
		System.out.printf("%5.2f和%5.2f的算术平均值：%5.2f\n", a, b, result);
		computer = new B();
		result = computer.average(a, b);
		System.out.printf("%5.2f和%5.2f的几何平均值：%5.2f\n", a, b, result);
	}

}
